JPS6015452B2 - Method for manufacturing lightweight structural materials covered with synthetic resin film - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a fiber-reinforced synthetic resin foam used as a lightweight structural material in building materials and the like.

Synthetic resin foam reinforced with fibers has a high mechanical strength,
Due to its lightness, workability and appearance similar to natural wood, it has begun to be used as a wood substitute for building materials. However, the above-mentioned lightweight structural materials do not have sufficient durability and are susceptible to deterioration due to direct sunlight and the like. For this reason, it has been conventional practice to cover the above-mentioned lightweight structural materials with a synthetic resin film in order to improve their weather resistance and durability, as well as to improve their appearance. As a method for continuously manufacturing lightweight structural materials coated with synthetic resin film, for example, as shown in Tsubaki Publication No. 48-130137, a resin liquid that foams and hardens in a short time is mixed with glass fiber or the like. A method is known in which the fibers are impregnated with the impregnated fibers, and the impregnated fibers are allowed to advance, and the surfaces thereof are covered with a surface covering material such as a synthetic resin film while being led to a molding passage and subjected to foaming and curing.

However, this method has the disadvantage that gas accumulates between the coating film and the molded product, causing bubbles to occur in places on the surface, impairing the appearance, and at the same time, the coating film tends to peel off from the product surface. The present invention was made in order to overcome the drawbacks of the method for continuously producing long fiber-reinforced synthetic resin foam whose surface is covered with a synthetic resin film, as described above, and its gist is to foam and harden in a short period of time. The surface of the fiber bundle impregnated with a resin solution that can be used is covered with a synthetic resin film in which holes with a diameter of 1 micron or more and 100 microns or more are provided at 1 to 5M or more per hole, and in this state, the resin solution is applied. The present invention relates to a method for producing a lightweight structural material coated with a synthetic resin film, which is characterized by foaming and curing.

In the present invention, a resin liquid that can foam and harden in a short period of time is used, but this resin liquid is initially liquid, and then hardens by heating etc., and has the property of foaming at the same time. A suitable curing agent or curing accelerator may be added to achieve this, and a reactive foaming agent, a thermally decomposable foaming agent, etc. may be added to achieve foaming.

Examples of the resin liquid suitable for use in the present invention include polyurethane, epoxy resin, and phenol resin. In addition, the above resin liquid is impregnated into the fibers, and the fibers used for this may be inorganic fibers such as glass fibers or carbon fibers, or synthetic resins such as polyamide, polyester, or polyolefin. The fibers may be made of natural fibers such as cotton, linen, wool, etc. Further, the fiber may be a single longitudinal fiber or a plurality of twisted fibers. However, for the purpose of using the lightweight structural material obtained by the method of the present invention as a substitute for wood, it is preferable to use long glass fibers as the fibers from the viewpoint of cost and physical properties. Next, as the synthetic resin film, a film made from ordinary synthetic resin such as polyolefin may be used, but in the present invention, the main purpose of the film is to protect lightweight structural materials for a long period of time. Therefore, it is preferable to use polyvinyl oxide from the viewpoint of surface protection against contact with pond objects and film resistance.

Further, the film may be subjected to some kind of treatment to improve adhesion to the resin surface after the resin liquid has hardened, such as coating with a substance that can increase affinity with the resin surface.
Radiation fin treatment, plasma treatment, etc. may be applied. However, the synthetic resin film used in the present invention has a diameter of 1
1 to 5 holes per 1 micron or more and 100 microns or less
It is established that more than 100 people are allowed.

If this hole is too small, gas will not be able to escape enough.
Furthermore, if the diameter is too large, the resin liquid may flow out, so the diameter is set to be 1 micron or more and 100 microns or less. If the number of holes is too large, the strength will decrease, so the number of holes is limited to 5q per hole. In the present invention, the synthetic resin film has 1 to 5 holes of 5 to 100 microns in diameter, and 1 to 5 holes of 20 to 50 microns in diameter.
It is preferable that the Further, the diameter and number of the holes may be determined as appropriate within the scope of the present invention based on the type of film and resin liquid used, molding conditions, etc. In order to produce a lightweight structural material coated with a synthetic resin film by the method of the present invention, the fibers are first impregnated with the resin liquid.

This impregnation may be carried out by any method, but it must be carried out before the resin liquid is foamed and hardened, and it is preferable to carry out the impregnation uniformly. Next, the textile cloth impregnated with the resin liquid is covered with the synthetic resin film, and in this state, the resin liquid contained in the fiber sheet is foamed and hardened to form a foamed molded article of the desired shape. . For this foaming and curing, conventionally known methods may be employed as appropriate; for example, heating may be performed, or cooling may be performed at the final stage of curing. In addition, any conventionally known appropriate method may be used to mold the resin-soaked fiber. However, in the present invention, from the viewpoint of continuously manufacturing products, the fiber bundles impregnated with resin liquid are aligned and continuously passed through a forming passage having a desired cross-sectional shape, and at the same time, continuously inserting the synthetic resin film from the entrance so that it is positioned between the inner surface of the passage and the fiber east, and foaming and hardening the resin liquid contained in the fiber bundle within the forming passage; It is preferable to adopt a method in which the fiber-reinforced foam formed into a desired shape and covered with a synthetic resin film is continuously taken out from the outlet of the passage.

As mentioned above, the method for producing lightweight structural materials of the present invention involves forming holes of 1 to 5 N per hole with a diameter of 1 micron or more and 100 microns or less on the surface of the fibers impregnated with a resin liquid that can be foamed and hardened in a short time. It is characterized in that it is coated with a synthetic resin film provided with a solid or more solid resin, and in this state, the resin liquid is foamed and cured. Smooth, lightweight structural materials can be produced continuously.

In addition, since there are no air bubbles between the lightweight structural material obtained by the method of the present invention and the coating film, not only does the adhesive strength between the film and the resin surface of the lightweight structural material main body be good, but also the adhesive strength of the film and the resin surface of the lightweight structural material body is good. By entering the resin into the holes, the bond becomes even stronger, and the coating film is less likely to peel off even after long-term use.

Furthermore, the holes provided on the surface of the covering film do not impair the protective ability of the covering film for the lightweight structural village body in any way, so the lightweight structural material coated with the synthetic resin film obtained by the present invention The surface is maintained for a long time and has excellent weather resistance. Examples of the present invention will be described below.

Example: 200 single glass fibers with a diameter of 9 mm were made into one strand, and 180 of these strands were collected.

A total of 2,000 tubes were lined up and moved continuously. Next, 10 parts by weight of polyether resin liquid, 1 part by weight of silicone oil, 1 part by weight of water, and 0 parts by weight of dibutyltin dilaurate.
．． A polyurethane resin solution containing 4 parts by weight and 12 parts by weight of 4,4-diphenylmethane di-socyanate was prepared, and the above long glass fiber East was impregnated with the resin solution.

In addition, the cream time of the above resin liquid is 1 at 20:00.
Tochisuna was 4 minutes long, the rise time was 2 minutes 3 minutes, and the set time was 6 minutes. The above-mentioned resin liquid-impregnated glass fibers are made of a tube made of iron plate on the 4 skins on the entrance side, and a cylinder made of many rolls on the 4 skins on the exit side, and an endless belt is provided along the inner wall, making the inner surface endless. The inner cavity made up of the belt advances through a molding passage with a length of 8w and a 100×low ship, and is further coated between the endless belt and the fiber east from the entrance of the molding passage along the endless belt. material was inserted.

Claims (1)

[Scope of Claims] 1. A fiber bundle impregnated with a resin liquid that can be foamed and hardened in a short time is formed on the surface of a fiber bundle with 1 to 50 holes per cm^2 having a diameter of 1 micron or more and 100 microns or less. 1. A method for producing a lightweight structural material covered with a synthetic resin film, which comprises covering the material with a resin film, and foaming and curing the resin liquid in this state. 2. The manufacturing method according to claim 1, wherein the synthetic resin film is a polyvinyl fluoride film. 3. The manufacturing method according to claim 1, wherein the synthetic resin film is provided with 1 to 50 holes with a diameter of 20 microns or more and 50 microns or less per cm^2.